Radiative lifetime measurements of rubidium Rydberg states

TL;DR

This study measures the radiative lifetimes of rubidium Rydberg states using advanced techniques in a MOT, providing precise experimental data that align well with theoretical predictions.

Contribution

The paper introduces a highly accurate method for measuring Rydberg state lifetimes, reducing errors and isolating specific state populations in rubidium atoms.

Findings

Results are consistent with recent experimental data.

Measurements agree closely with theoretical calculations.

Method effectively isolates target state populations.

Abstract

We have measured the radiative lifetimes of ns, np and nd Rydberg states of rubidium in the range 28 < n < 45. To enable long-lived states to be measured, our experiment uses slow-moving Rb atoms in a magneto-optical trap (MOT). Two experimental techniques have been adopted to reduce random and systematic errors. First, a narrow-bandwidth pulsed laser is used to excite the target Rydberg state, resulting in minimal shot-to-shot variation in the initial state population. Second, we monitor the target state population as a function of time delay from the laser pulse using a short-duration, millimetre-wave pulse that is resonant with a one- or two-photon transition. We then selectively field ionize the monitor state, and detect the resulting electrons with a micro-channel plate. This signal is an accurate mirror of the target state population, and is uncontaminated by contributions from other states which are populated by black body radiation. Our results are generally consistent with other recent experimental results obtained using a less sensitive method, and are also in excellent agreement with theory.